<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>百度换肤案例</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        body {
            background: url(精灵图.PNG) repeat  center top ;
        }
        li {
            list-style: none;
        }
        .baidu {
            overflow: hidden;
            margin: 100px auto;
            background-color: #fff;
            width: 310px;
            padding-top: 3px;
        }
        .baidu li {
            float: left;
            margin: 0 1px;
            cursor: pointer;
        }
        .baidu img {
            width: 100px;
            height: 100px;
        }
    </style>
</head>
<body>
    <ul class="baidu">
        <li><img src="精灵图.PNG" alt=""></li>
        <li><img src="img.png" alt=""></li>
        <li><img src="my.png" alt=""></li>
    </ul>
    <script>
        var imgs = document.querySelector('.baidu').querySelectorAll('img')
        for (var i = 0; i < imgs.length; i++){
            imgs[i].onclick = function() {
                document.body.style.backgroundImage =  'url(' + this.src +')'
            }
        }
    </script>
</body>
</html> 